11th ICRS Abstract book - Nova Southeastern University

Oral Mini-Symposium 17: Emerging Techniques in Remote Sensing and Geospatial Analysis
17-29
Semi-Automated Classification Of Acoustic & Optical Remotely Sensed Imagery in
The U.s. Caribbean
Bryan COSTA* 1 , Tim BATTISTA 1 , Charles MENZA 1
1 Biogeography Branch, NOAA/NOS/NCCOS/CCMA, Silver Spring, MD
Benthic habitat mapping supports ecosystem-based management objectives by
contributing to the development of detailed species utilization models linking physical
habitats with biological information. Marine habitats deeper than 30 meters have been
successfully characterized by conducting heads-up digitizing of acoustic and optical
remotely sensed imagery. These resulting maps, however, are subjective and ultimately
irreproducible because they depend on the accuracy and interpretation of the person that
is digitizing. Here we semi-automate the seafloor feature extraction and classification
process using high-resolution MBES and LiDAR data as well as underwater images
collected off the coast of western Puerto Rico. Alternative approaches were used to
identify and extract seafloor features at relevant spatial and thematic scales. The
accuracy of these mid to deep-water benthic habitat maps were validated using
georeferenced underwater imagery. The ability to quickly and objectively create benthic
habitat maps would allow scientists and resource managers to better quantify and assess
the changing health of mid to deep-water coral reef ecosystems.
17-30
Mapping Marine Habitats in The Largest Reef Area Of Southern Atlantic: The
Abrolhos Bank, Brazil
Daniel KLEIN 1 , Alex BASTOS 2 , Guilherme DUTRA* 3 , John MUSINSKY 4 , Ruy
KIKUCHI 5 , Rodrigo MOURA 6
1 Marine Management Areas Science Program, Conservation International / UFBA,
Caravelas, Brazil, 2 Laboratório de Oceanografia Geológica, DERN, UFES, Vitória,
Brazil, 3 Marine Program, Conservation International Brazil, Salvador, Brazil, 4 CABS,
Conservation International, Arlington, VA, 5 Centro de Pesquisas em Geofísica e
Geologia, UFBA, Salvador, Brazil, 6 Marine Program, Conservation International Brazil,
Caravelas, Bahia, Brazil
The Abrolhos Bank is the largest and richest coral reef area in the South Atlantic,
covering 46,000 km 2 of shallow waters (up to 100 m deep) in the Northeastern Brazilian
Continental Shelf. The region bears a mosaic of estuaries, mangrove forests and coralline
reefs, as well as rodolith, grass, algae and muddy beds. Despite its importance, most of
the bank remains unmapped in terms of the extension and distribution of its habitats, with
the exception of emergent coralline reefs mapped in coarse scale with remote sensing
(TM Landsat). This situation represents a major impediment for effective conservation
planning, zoning and monitoring of marine managed areas. The project described herein
is producing finer scale maps covering Abrolhos’ main marine habitats with use of side
scan sonar (Edgetech) surveys at two different scales: 1) East-West transects from
shallow areas (20 m) to the shelf break, each transect spaced by 10 km (100 kHz); 2)
finer scale mapping between the initial transects, in areas with hard bottom structures and
higher habitat heterogeneity (500 kHz). Subsequent ground truth with targeted SCUBA
dives, ROV (Remotely Operated Vehicle) and bottom grabbers are assisting habitat
classification. Preliminary results are showing extensive areas of unmapped reefs (hard
structures), as well as a great habitat diversity in inter-reefal areas. Paleochannels and
other more isolated depressions were also recorded and observed along the Bank’s plains.
Habitats’ maps resulting from these surveys will be critical for developing strategies for
the sustainable use of the region’s unique seascape.
17-31
Single Beam Acoustic Remote Sensing For Coral Reef Mapping
Arthur GLEASON* 1 , Pamela REID 1 , Todd KELLISON 2
1 Marine Geology and Geophysics, University of Miami / RSMAS, Miami, FL, 2 NOAA
Southeast Fisheries Science Center, Miami, FL
Coral reef habitats that cannot be mapped with optical techniques are both extensive and
ecologically important. For example, over 55% of the Florida Keys National Marine Sanctuary
(about 1540 square nautical miles) has not been mapped due to water depth or clarity
limitations. Acoustic mapping systems are the natural solution to mapping optically deep water,
and inexpensive commercial single beam seabed mapping systems are available. Several studies
have used commercial single beam systems to map coral reefs, but basic questions about what
substrates can be reliably distinguished and how consistent classification schemes are in
different areas have not been systematically explored. We have used one commercial system,
the Quester Tangent Series V (QTCV) to begin answering such questions. QTCV datasets from
the Florida Keys, USA, the Bahamas, and Navassa Island reveal that rock and sediment are
almost always reliably distinguished and that sediment grain size and high seabed relief are
other factors captured by classification results. Moderate resolution (~100 m transect spacing)
surveys in the Florida Keys are sufficient to delineate the extent of outlier reefs and to
differentiate two distinct outlier reef morphologies: patches and linear ridges. Due to their low
cost and portability, single beam systems can play a valuable role in coral reef mapping efforts,
efficiently providing rapid reconnaissance and moderate resolution habitat maps of large areas.
17-32
Characterization And Monitoring Of Insular Shelf Reefs in Optically-Deep Waters
Roy ARMSTRONG* 1 , Maria CARDONA 1 , Hanumant SINGH 2 , Sara RIVERO 1 , Fernando
GILBES 1
1 University of Puerto Rico, Mayaguez, Puerto Rico, 2 Woods Hole Oceanographic Institution,
Woods Hole, MA
Although remote sensing technology is a useful tool for monitoring shallow (